1. Reference to Related Applications
This application claims the right of priority based on TW application Serial No. 104141037, filed on Dec. 8, 2015, and the content of which is hereby incorporated by reference in its entirety.
2. Field of the Invention
The present invention relates to a roll-to-roll sputtering process with a hybrid target and a product thereof, and more particularly, to a roll-to-roll sputtering process with a hybrid target and a product thereof using the hybrid target formed by a variety of metals sequentially to process sputtering and produce products.
3. Description of the Prior Art
In the prior art, the process of roll-to-roll is unwinding raw flexible material through an unwinding axis from a cylindrical retracting flexible material to be processed, through processing operations, such as, precision stamping, laminating, coating, printing and other processing operations, and then the flexible material completed processing is rewinded through the rewinding axis. Due to the convenience of rewinding and unwinding raw material and finished product, it is considered as a high performance and low cost continuous production mode, which is even popular with the flexible electronic product manufacturing industry.
Taking coating as an example; a coating process during unwinding-rewinding process can be used to produce flexible transparent conductive film such as ITO film used in touch panels or the electrodes used in blood glucose test strip. When producing a multilayer flexible transparent conductive film, each layer of the conductive film is sputtered on almost the entire surface of the flexible material separately. Several repeated coating operations are needed for all layers in order to complete the coating process.
However, when producing the blood glucose test strips, each piece of blood glucose test strips needs to have at least one pair of electrodes (such as working and counter electrodes) and extending conductive wires of the electrodes (extending electrode) at the same time, and the area occupied by each electrode varies. Basically, because the metal used for working electrode and counter electrode should be very stable and chemical inert, precious metal such as gold, platinum or palladium normally is used for producing the working and counter electrodes. Precious metal is very expensive compared to normal metal or current mostly used carbon electrode. However, normal metal such as copper or its alloy with good electric conductive property is good to be used for the extending electrode with low cost. If using the conventional sputtering process of producing flexible transparent conductive film to produce the blood glucose test strips, precious metal should be used for the entire strip on both the working electrode and the extending electrode area due to the electrode stability requirement. Considering of the cost, the entire precious metal strip is lack of competition ability in the blood glucose test strip market. An idea for reducing the cost and still keeping the stability of the test strip's electrodes is to coat the precious metal on the working electrode and the normal metal on the extending electrode separately. However, the difficulty to use the conventional sputtering process to produce such kind of blood glucose test strips is that it needs to have different metal precisely positioned on the working and extending electrode in several coating operations. In other words, the different metal for the working electrode and the extending electrode needs to be coated precisely on different partial surface of the entire flexible material by several coating processes first, and then to remove the unnecessary portion of the metal film. This process may not only increase the complexity of the processes but also result in overlapping, and there may be mutual interference between each coating operation.
In conclusion, a process that can complete all coating operations in one time to avoid the overlapping and mutual interference is needed to reduce the time and the cost of manufacturing.